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211.
The addition reactions of pentafluorothiophenol, C6F5SH, and pentafluorobenzenesulfenyl choloride, C6F5SCl, with various unsaturated systems, including alkenes, alkynes, oxiranes, thiiranes, diazo compounds, aldehydes, ketones, and nitriles have been examined. The physical properties of the new compounds are reported together with some spectroscopic data. 相似文献
212.
213.
Theng Choon Ooi Farah Wahida Ibrahim Shakirah Ahmad Kok Meng Chan Lek Mun Leong Nihayah Mohammad Ee Ling Siew Nor Fadilah Rajab 《Molecules (Basel, Switzerland)》2021,26(11)
Ficus deltoidea var. deltoidea is used as traditional medicine for diabetes, inflammation, and nociception. However, the antimutagenic potential and cytoprotective effects of this plant remain unknown. In this study, the mutagenic and antimutagenic activities of F. deltoidea aqueous extract (FDD) on both Salmonella typhimurium TA 98 and TA 100 strains were assessed using Salmonella mutagenicity assay (Ames test). Then, the cytoprotective potential of FDD on menadione-induced oxidative stress was determined in a V79 mouse lung fibroblast cell line. The ferric-reducing antioxidant power (FRAP) assay was conducted to evaluate FDD antioxidant capacity. Results showed that FDD (up to 50 mg/mL) did not exhibit a mutagenic effect on either TA 98 or TA 100 strains. Notably, FDD decreased the revertant colony count induced by 2-aminoanthracene in both strains in the presence of metabolic activation (p < 0.05). Additionally, pretreatment of FDD (50 and 100 µg/mL) demonstrated remarkable protection against menadione-induced oxidative stress in V79 cells significantly by decreasing superoxide anion level (p < 0.05). FDD at all concentrations tested (12.5–100 µg/mL) exhibited antioxidant power, suggesting the cytoprotective effect of FDD could be partly attributed to its antioxidant properties. This report highlights that F. deltoidea may provide a chemopreventive effect on mutagenic and oxidative stress inducers. 相似文献
214.
Synthesis,Characterization, and Crystal Structures of Diruthenium Complexes Containing Bridging Salicylato Ligands
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Mingxuan Jiang Chun Huan Yau Yuxin Hu Yong Leng Kelvin Tan Yingzhou Li Rakesh Ganguly Weng Kee Leong 《无机化学与普通化学杂志》2017,643(14):878-882
The thermal reaction of Ru3(CO)12 ( 1 ) with salicylic acid, in the presence of triphenylphosphine, pyridine, or dimethylsulfoxide, afforded the dinuclear complexes Ru2(CO)4(μ‐O2CC6H4OH)2L2 ( 2 ) [L = PPh3 ( 2a ). C5H5N ( 2b ); (CH3)2SO ( 2c )]. Complex 2b was further reacted with the aromatic dimmines 2,2′‐dipyridine or 1,10‐phenanthroline to give the cationic diruthenium complexes [Ru2(CO)2(μ‐CO)2(μ‐O2CC6H4OH)(N∩N)2]+ ( 3 ) [(N∩N) = 2,2′‐dipyridine ( 3a ); 1,10‐phenanthroline ( 3b )], which were isolated as their tetraphenylborate salts. All five novel complexes were characterized spectroscopically and analytically. For 2a – 2b and 3a – 3b , single‐crystal X‐ray diffraction studies were also carried out. 相似文献
215.
Both two and eighteen dimensional quantum diffusion Monte Carlo (DMC) calculations were used to study the isomers of hydroxyacetaldehyde. A total of four unique minima, and the transition states connecting them, were located. Both two and eighteen dimensional potential energy surfaces were generated and used in the DMC runs. The rotational constants for the global minimum were predicted for all experimentally identified isotopomers and an approximate equilibrium structure obtained by combining our theoretical results with the experimentally observed rotational constants. The results obtained for the remaining isomers indicate that not all of them can be isolated in the gas phase. 相似文献
216.
A two-stage Tikhonov regularisation procedure has been used to obtain rheological properties for a high internal phase emulsion
from gap-dependent steady-state parallel plate shear data. This method is beneficial in that it can convert the steady shear
data into rheological property functions. The built-in regularisation parameters of the method are able to keep noise amplification
under control. The two-stage method is able to obtain not only the shear stress–shear rate function but also the apparent
slip velocity as a function of wall shear stress. The method is such that it obtains the rheological functions over the maximum
range of shear rate covered by the data. The results obtained using the new method are compared to those obtained using the
vane geometry with good agreement being observed. 相似文献
217.
218.
This paper describes the development of an experimental facility to determine the heat transfer and flow friction characteristics
of heat exchange surfaces by the modified single blow technique and the application of this transient technique to evaluate
the performance characteristics of louvered fin heat exchangers. The reliability of implementing the modified single blow
technique on the developed test facility is borne out by the good agreement in the heat transfer and flow friction data for
the parallel plate test core when compared with theoretical and empirical correlations available in the literature. Performance
evaluation of two louvered fin surfaces used mainly for cooling of large land and marine based electrical power generator
sets is carried out and compared with similar louvered fin surfaces available in the literature. On the basis of dimensionless
area and power factors, it was found that the flat fin is slightly superior in overall performance than its corrugated counterpart
for low Reynolds numbers. Both surfaces are however inferior in performance when compared with the flat fin surface of Achaichia
and Cowell and the corrugated fin surface of Davenport. Use of the j/f ratio as an approximate figure of merit led to an inaccurate assessment of the performance of the louvered fin heat exchanger
surfaces evaluated in this study.
Received on 8 May 1998 相似文献
219.
Repeat-until-success linear optics distributed quantum computing 总被引:1,自引:0,他引:1
We demonstrate the possibility to perform distributed quantum computing using only single-photon sources (atom-cavity-like systems), linear optics, and photon detectors. The qubits are encoded in stable ground states of the sources. To implement a universal two-qubit gate, two photons should be generated simultaneously and pass through a linear optics network, where a measurement is performed on them. Gate operations can be repeated until a success is heralded without destroying the qubits at any stage of the operation. In contrast with other schemes, this does not require explicit qubit-qubit interactions, a priori entangled ancillas, nor the feeding of photons into photon sources. 相似文献
220.
Jian Su Shuai Yuan Jing Li Hai-Ying Wang Jing-Yuan Ge Hannah F. Drake Chanel F. Leong Fei Yu Prof. Dr. Deanna M. D'Alessandro Prof. Dr. Mohamedally Kurmoo Prof. Dr. Jing-Lin Zuo Prof. Dr. Hong-Cai Zhou 《Chemistry (Weinheim an der Bergstrasse, Germany)》2021,27(2):622-627
Using the redox-active tetrathiafulvalene tetrabenzoate (TTFTB4−) as the linker, a series of stable and porous rare-earth metal–organic frameworks (RE-MOFs), [RE9(μ3-OH)13(μ3-O)(H2O)9(TTFTB)3] ( 1-RE , where RE=Y, Sm, Gd, Tb, Dy, Ho, and Er) were constructed. The RE9(μ3-OH)13(μ3-O) (H2O)9](CO2)12 clusters within 1-RE act as segregated single-molecule magnets (SMMs) displaying slow relaxation. Interestingly, upon oxidation by I2, the S=0 TTFTB4− linkers of 1-RE were converted into S= TTFTB.3− radical linkers which introduced exchange-coupling between SMMs and modulated the relaxation. Furthermore, the SMM property can be restored by reduction in N,N-dimethylformamide. These results highlight the advantage of MOFs in the construction of redox-switchable SMMs. 相似文献